JPH01297335A - Trouble judging device for driver protecting system for vehicle - Google Patents

Abstract

PURPOSE:To distinctly judge the existence of a trouble in each part in a starting circuit system by generating a plurality of pseudo signals which are different for a standard level, in the system which operates when the detection level for accelerating speed exceeds the standard level. CONSTITUTION:In a driver protecting system such as gas bag system, if a means 4 judges that the accelerating speed of a vehicle which is detected by a means 3 is over a standard level, a means 5 supplies electricity into a starting element 2a from a dc power source 1, and an operating mechanism 2 operates to protect a driver. In this case, only the signals supplied into the means 4 from the means 3 are received by a means 6. Further, a plurality of pseudo signals which are different for a standard level are generated by the means 7 and 8. When each pseudo signal is generated, a means 9 selectively judges the existence of the trouble in an input circuit system and the residual circuit system in the correlation with the standard level on the basis of the output level of each means 3, 6.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an occupant protection system such as a gas bag system for a vehicle, and more particularly, to a failure determination device for determining whether or not an occupant protection system has a failure. Regarding.

(Prior Art) Conventionally, in this type of failure determination device, in order to improve the reliability of the gas bag system, the activation device of the gas bag system is put into a pseudo-operable state by inputting a pseudo signal to determine whether or not there is a failure. That's what I do. In such cases, the presence or absence of the above-mentioned failure has usually been determined by inputting a pseudo signal into the activation determination circuit of the starter device or by generating a signal from a transducer. (For example, see Japanese Patent Publication No. 50-14772).

(Problems to be Solved by the Invention) However, in such a configuration, when a pseudo signal is input to the operation determination circuit, it is not possible to determine whether there is a failure between the l transducer and the operation determination circuit. Furthermore, when a signal is generated from a transducer, a problem arises in that it is unclear whether or not the activation of the activation device is due to its failure.

Therefore, in order to cope with such a problem, the present invention provides a failure judgment device for a vehicle occupant protection system that detects failures of various parts in a circuit system that starts a starting element in an activation mechanism for protecting an occupant. The purpose is to distinguish between the presence and absence of paper and fold it into paper sheets.

(Means for solving the problem) In solving the problem, the structural features of the present invention are as follows:
As illustrated in FIG. 1, the vehicle has a starting element 2a that is installed in the passenger compartment of the vehicle and is selectively activated according to the inflow current from the DC power source 1, and the occupant is activated in response to the activation of the starting element 2a. an actuation mechanism 2 that operates to protect the vehicle; an acceleration detection means 3 that detects the acceleration of the vehicle and generates an acceleration detection signal; and a current supply means 5 for supplying current from the DC power source 1 to the starting element 2a in response to the determination signal.
a signal application permitting means 6 that only permits the application of a signal to the reference level;
A second difference having a level in the opposite direction to the first difference level with the reference level as a reference is provided between the first pseudo signal generation means 7 for generating a pseudo signal, the signal provision permitting means 6 and the determination means 4. a second pseudo signal generating means 8 for generating a second pseudo signal at a certain level;
When a gi-like signal is generated, it is determined whether or not there is a failure in the input circuit system based on the output levels of the acceleration detection means 3 and the signal provision permitting means 6 in relation to the reference level, and when the first pseudo-signal disappears. and determining means 9 for determining whether or not there is a failure in the remaining circuit system based on the input/output level of the signal provision permitting means 6 in relation to the reference level when the second pseudo signal is generated. It is in.

(Function) By configuring the present invention in this way, the first pseudo signal generating means 7 generates the first pseudo signal to accelerate the acceleration detecting means 3 when the second pseudo signal from the second pseudo signal generating means 8 disappears. When a pseudo acceleration detection signal is generated from the input circuit, the determination means 9 determines whether or not there is a failure in the input circuit system based on the respective output levels of the acceleration detection means 3 and the signal provision permitting means 6 in relation to the reference level. . Further, when the second pseudo signal is generated from the second pseudo signal generating means 8 while the first condensed signal from the first pseudo signal generating means 7 disappears,
A determining means 8 determines whether or not there is a failure in the remaining circuit system based on the input/output level of the signal provision permitting means 6 in relation to the reference level.

(Effects) In this way, by employing the first and second pseudo signal generating means 7.8, the acceleration detection signal pseudo-generated from the acceleration detecting means 3 based on the first condensed signal in the normal state. level and the level of the second pseudo signal by the determining means 4
Since the judgment means 9 makes the judgment as described above, the judgment result of the judgment means 9 is different from the reference level. Due to this relationship, different results are obtained in the case of a failure in the input circuit system and in the case of a failure in the remaining circuit system. For this reason,
Even without a normal output from the acceleration detection means 3, it is possible to identify and recognize the presence or absence of a failure in the input circuit system of the device of the present invention and the presence or absence of a failure in the remaining circuit system.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.
Figures 1 and 3 show an example of the overall configuration of a vehicle gas bag system, and this gas bag system consists of a gas bag Bg installed on the vehicle's steering handle It is composed of a gas generator G and a starting device S according to the present invention, which is provided in a control box Bc in the cabin of the vehicle. The gas generator G has a built-in starting element 10, and this gas generator G ruptures in response to heat generation energy caused by the current flowing into the starting element 10, and releases gas from a gas storage source (not shown). It is rapidly supplied into the gas bag 8g to inflate the gas bag Bg.

The starting device S has a transducer 20 which detects the actual acceleration of the vehicle and produces an acceleration detection signal at its output terminal 22. The l-transducer 20 is put into operation by being supplied with a power supply voltage from the pantry Ba through the fuse F and the ignition switch IG of the vehicle at its power supply terminal 21. The amplifier 20a amplifies the acceleration detection signal from the transducer 20 and generates an acceleration amplified signal. The buffer 20b is biased in the forward direction in response to the amplified acceleration signal from the amplifier 20a, becomes conductive, and generates the amplified acceleration signal as an acceleration buffer signal. Also,
Buffer 20b becomes non-conductive due to reverse bias.

The operation determination circuit 30 includes a comparator 31 and
This comparator 31 determines that the level of the acceleration buffer signal from the buffer 20b is determined by the pair of series resistors 31a and 31b.
Low level (low level) when lower (or higher) than the reference voltage from
or high level) to generate a comparison signal. A pair of series resistors 31a and 31b are connected to a constant voltage (+V c
) is divided and generated as the reference voltage. In such case,
- the reference voltage from the pair of series resistors 31a, 31b corresponds to an acceleration somewhat lower than the acceleration of the vehicle required to inflate the gas bag Bg; In the integrating circuit 32, when the comparison signal from the comparator 31 changes to high level, the capacitor 32a is charged by receiving a constant voltage from the constant voltage power supply through the high resistances 32b and 32C.

This means that the capacitor 32a generates the charging voltage as an integrated voltage at a common terminal with the resistor 32G. Further, the charging voltage of the capacitor 32a drops instantaneously through the resistor 32c due to the change of the comparison signal from the comparator 31 to low level.

The comparator 33 generates a comparison signal at a high level (or low level) when the integrated voltage from the capacitor 32a is lower (or higher) than the reference voltage from the pair of series resistors 33a and 33b. - a pair of series resistors 33a, 33b;
is generated as the reference voltage by dividing the constant voltage from the constant voltage power supply.

In this case, the reference voltage from the pair of resistors 33a and 33b corresponds to the voltage necessary to determine the necessity of inflating the gas bag Bg. The actuation switch circuit 40 includes a transistor 4
1 and a high resistance 42 connected between the emitter and collector of this transistor 41, and the L transistor 41 is configured with a high resistance 42 connected between the emitter and collector of this transistor 41.
3a, and its collector is connected to one terminal 11 of the starting element 10. Thus, the transistor 41 becomes conductive in response to the low-level comparison signal from the comparator 33 to short-circuit the high resistance 42, and the short-circuit is canceled by becoming non-conductive in response to the high-level comparison signal from the comparator 33. .

The failure detection circuit 50 has a comparator 51,
This comparator 51 generates a comparison signal at a high level (or low level) when the level of the acceleration amplified signal from the amplification W20a is higher (or lower) than the reference voltage from the pair of series resistors 51a and 51b. A pair of series resistors 51
a and 51b divide the constant voltage from the constant voltage power supply to generate the reference voltage. In such a case, when a pseudo signal is generated from the pseudo signal generation circuit 80 as described later, the reference voltage from the pair of series resistors 51a, 51b is determined as follows: reference voltage from the pair of series resistors 31a, 31b>acceleration from the amplifier 20a The level of the amplified signal is set to be lower than the level of the same acceleration amplified signal. That is, the comparator 51 detects the acceleration amplified signal from the pseudo signal generation circuit 80 and outputs a comparison signal at a high level, and the comparator 31 detects the acceleration amplified signal from the pseudo signal generation circuit 80.
A high-level comparison signal is not output with the acceleration amplified signal. The comparator 52 determines whether the level of the pseudo signal generated from the pseudo signal generation circuit 60 as described later is higher (or lower) than the reference voltage from the pair of series resistors 52a and 52b.
A comparison signal is generated at high level (or low level). A pair of series resistors 52a and 52b divides the constant voltage (+-Vc) from the constant voltage power supply to generate the reference voltage. In such a case, a pair of series resistors 52a, 52b
The reference voltage from the pair of series resistors 51a, 51b is equal to the reference voltage from the pair of series resistors 51a, 51b.

The comparator 53 generates a comparison signal at a high level (or low level) when the terminal voltage from one end 11 of the starting element 10 is higher (or lower) than the reference voltage from the pair of series resistors 53a, 53b.

A pair of series resistors 53a and 53b divides the constant voltage (+Vc) from the constant voltage power supply to generate the reference voltage. In such a case, the reference voltage from the pair of series resistors 53a and 53b is determined by considering the ratio of the resistance value of the high resistor 42 to the sum of the resistance value of the starting element 10 and the resistance value of the high resistor 72 of the inhibit switch circuit 70. It is determined that Therefore, when the transistor 71 of the inhibit switch circuit 70 is non-conductive while the transistor 41 is conductive, the terminal voltage generated at one terminal 11 of the starting element 10 becomes higher than the reference voltage from the pair of series resistors 53a and 53b. Then, the comparator 53 is
The voltage divided between the high resistance 42, the starting element 10, and the high resistance 72 outputs a comparison signal at a low level, and the high resistance 42 is short-circuited by the I transistor 41, and the terminal 1 of the starting element 10 is short-circuited.
1 approximately reaches the voltage of the power supply Ba, a comparison signal is output at a high level. The microcomputer 54 executes the computer program in cooperation with the comparators 51, 52, and 53 according to the flowchart shown in FIG. Performs arithmetic processing necessary for controlling the switch circuit 70. Note that the computer program is stored in the ROM of the microcomputer 54 in advance.

The transistor 55 is selectively turned on under the control of the microcomputer 54 to light up the warning lamp La (see FIGS. 2 and 3). The inhibition switch circuit 70 is composed of an l-rangestaff 1 and a high resistance 72 connected between the emitter and collector of this transistor 71.
Under the control of the microcomputer 54, the transistor 71 is selectively turned on to short-circuit the high resistance 72, and the short-circuit is canceled by being turned off. The emitter of this transistor 71 is grounded, while the collector' of this L-disk 71 is connected to the other end 12 of the starting element 10. Therefore, when the measuring resistors 42 and 72 are shorted together, the power supply current from the battery Ba is transferred to the fuse F.
, ignition switch IG and l transistor 41
, and flows into the starting element 10 with the required amount of current necessary for its starting. Further, when the short circuit of one of the measurement resistors 42.72 is released, the current flowing into the starting element 10 is suppressed to a minute current.

The pseudo signal generation circuit 60 includes a transistor 61 and a resistor 6.
2, the transistor 61 is connected at its emitter to the positive terminal of the battery Ba through the ignition switch IG and the fuse F;
Its collector is connected to the non-inverting input terminal of the comparator 52 via a resistor 62. Thus, transistor 61 is selectively rendered conductive under the control of microcomputer 54. Resistor 62 generates a pseudo signal in response to conduction of transistor 61 and applies it to connection point 63 . In such a case, when the transistor 61 becomes conductive, the level of the pseudo signal from the resistor 62 becomes equal to that of each pair of series resistors 31 a,
3 l b, 33 a, 33 b, and 52 a
, 52b, the resistance value of the resistor 62 is set to be higher than any of the reference voltages from the resistors 62b and 52b. The pseudo signal from resistor 62 disappears as transistor 61 becomes non-conductive.

The pseudo signal generation circuit 80 includes a transistor 81 and a resistor 8.
The transistor 81 has its emitter grounded, and its collector connected to the input terminal of the amplifier 20a through a resistor 82. Therefore, the L transistor 81 is connected to the microcomputer 54.
conducts selectively under the control of The resistor 82 generates a pseudo signal in response to the conduction of the transistor 81 and the amplifier 2
Assigned to input terminal 0a. In such a case, the resistance value of the resistor 82 is determined by the following formula: 1. When the transistor 81 is conductive, the reference voltage from the pair of series resistors 31a and 31b>the level of the acceleration amplified signal from the amplifier 20a>the pair of series resistors 51a and 5
It is set to be the reference voltage from 1b. The pseudo signal from resistor 82 disappears as transistor 81 becomes non-conductive.

In this embodiment configured as described above, when the ignition switch IG is closed during the primary check of the device of the present invention, the microcomputer 54 is supplied with power from the pantry Ba and is put into operation, at step 100 according to the flowchart of FIG. Start running a computer program. Next, microcomputer 5
4, in step 101, the first output signal for making the l.
At 02,
Generates an output signal. Then, the transistor 71 is turned off to the microcomputer 54 while the transistor 41 is non-conducting.
It becomes non-conductive based on the disappearance of the first output signal from the first output signal. Therefore, the current flowing into the starting element 10 from the battery Ba becomes a very small current due to the relationship with the picture resistor 42.72.

Further, as mentioned above, the second
When an output signal is generated, the transistor 81 of the pseudo signal generation circuit 80 becomes conductive and generates a pseudo signal from the resistor 82, and the amplifier 20a, in relation to the pseudo signal from the resistor 82,
- An acceleration amplification signal is generated when the acceleration detection signal from the transducer 20 disappears, and the barnofer 20b generates an acceleration buffer signal. In such a case, the level of the acceleration buffer signal is determined by the pair of series resistors 31 of the operation determination circuit 30 in relation to the pseudo signal from the pseudo signal generation circuit 80.
Since it is lower than the reference voltage from a, 31b, the comparison signal produced by the comparator 31 is at a low level. Therefore, the l transistor 41 will not become conductive.

As described above, each comparator 51,52 generates a respective comparison signal when the acceleration amplified signal and the acceleration buffered signal are generated from amplifier 20a and buffer 20b, respectively. In such a case, the level of the acceleration amplified signal is the same as that of the pair of series resistors 51a.

A pair of series resistors 52a whose level is higher than the reference voltage from 51b and the level of the acceleration buffer signal is higher than the reference voltage from 51b.

If the voltage is higher than the reference voltage from 52b, both comparison signals from both comparators 51 and 52 become high level.

This means that the circuit system (hereinafter referred to as circuit system A) including the transducer 20° amplifier 20a and buffer 20b is normal. On the other hand, if the respective comparison signals from both comparators 51 and 52 both become low level, it means that there is a failure in the circuit system A. Examples of this failure include, for example, the transducer 20 and the amplifier 20.
An example of this is a disconnection of the connection line with a.

Furthermore, if the comparison signal from the comparator 51 becomes high level and the comparison signal from the combiner 52 becomes low level, it means that there is a failure in the input/output system of the buffer 20b (hereinafter referred to as circuit system B). . An example of this failure is a break in the input connection line or output connection line of the buffer 20b.

When the computer program proceeds to step 103, the microcomputer 54 determines the level of the comparison signal from each comparator 51, 52.

Therefore, if the comparison signals from both comparators 51 and 52 are both low level, the microcomputer 54
advances the computer program to step 104;
It is determined that there is a failure in the circuit system A, and in step 105, a first warning signal is generated to continuously light the warning lamp La to indicate the failure of the circuit system A, and the transistor 55 turns on the warning lamp due to its conduction. Light up La continuously.

Thereby, it can be visually recognized that there is a failure in the circuit system A.

Further, when the computer program advances to the steering knob 103 as described above, if the comparison signal from the comparator 51 is at high level and the comparison signal from the comparator 52 is at low level, the micro combiator 54
The computer program proceeds to step 106, where it is determined that there is a failure in the circuit system B, and at step 107, a second W is executed to intermittently light the warning lamp La at the first intermittent time to indicate the failure of the circuit system B. generates a warning signal,
The transistor 55 is intermittently conductive during the first intermittent time period, causing the warning lamp La to be lit intermittently.

As a result, it is possible to visually confirm that there is a failure in the circuit system B.

Further, when the computer program proceeds to step 103 as described above, if the respective comparison signals from both comparators 51 and 52 are both at a high level, the microcomputer 54 causes the computer program to proceed to step 108. This means that the computer program is executed at step 10 based on the judgment that there is no failure in circuit system A.
This means proceeding to 8. Therefore, in step 108, the microcomputer 54 eliminates the second output signal and generates a third output signal for making the l.transistor 1 conductive. Then, the L transistor 81 becomes non-conductive in response to the disappearance of the second output signal from the microcomputer 54, thereby causing the pseudo signal from the resistor 82 to disappear, thereby causing the acceleration amplified signal from the amplifier 20a to disappear. Further, the transistor 6 of the pseudo signal generation circuit 60
1 generates a pseudo signal from the conducting resistor 62 in response to the third output signal from the microcomputer 54. In such a case, the comparison signal from the comparator 51 is
Based on the disappearance of the acceleration amplified signal from the amplifier 20a under non-conduction of 0b, the comparator 52 is at a low level regardless of the pseudo signal from the pseudo signal generation circuit 60.
The comparison signal from the pseudo signal generation circuit 60 becomes high level based on the reference voltage from the pair of series resistors 52a and 52b, and the level of the pseudo signal from the pseudo signal generation circuit 60 becomes high.
The relationship between the comparison signal from the pseudo signal generation circuit 60 and the terminal voltage generated at one terminal 11 of the starting element 10 under conduction of the transistor 41 which responds to the low level comparison signal generated from the comparator 33 based on the pseudo signal from the pseudo signal generation circuit 60 If the level becomes high, both the circuit system B and the circuit system including the operation determination circuit 30 and the operation switch circuit 40 (hereinafter referred to as circuit system C) are normal. Further, if the comparison signal from the comparator 52 becomes high level and the respective comparison signals from both comparators 51 and 53 are both low level, there is a failure in the circuit system C (for example, a disconnection in the operation determination circuit 30). It turns out. Furthermore, if the comparison signal from the comparator 51 becomes high level, there is a failure in the circuit system B (for example, a short-circuit failure in the buffer 20b).
Otherwise, there is a conduction failure in the transistor 81.

When the computer program proceeds to step 109, the microcomputer 54 selects each comparator 51, 52 .
The level of the comparison signal from 53 is determined. If the comparison signal from the comparator 51 is at a high level, the microcomputer 54 advances the computer program to step 11O to determine if the circuit system B is out of order or
- It is determined that there is a conduction failure in the lamp disc 81, a second warning signal is generated in step 107, and the transistor 55 lights the warning lamp La intermittently during the first intermittent time. This may cause failure of circuit system B or failure of transistor 8.
1 continuity failure can be visually confirmed.

Further, when the computer program proceeds to step 109 as described above, if the comparison signal from the comparator 52 is at a high level and the respective comparison signals from both comparators 51 and 53 are at a low level, the microcomputer 54 runs the computer program step 11
1, it is determined that there is a failure in the circuit system C, a third warning signal is generated in step 112 to cause the warning lamp La to be lit intermittently during the second intermittent time () the first intermittent time), and the transistor 55 is intermittently conductive during the second intermittent time period, causing the warning lamp La to be lit intermittently. Thereby, it can be visually recognized that there is a failure in the circuit system C.

Further, when the computer program proceeds to step 109 as described above, if the comparison signal from the comparator 51 is at a low level and the respective comparison signals from both comparators 52 and 53 are at a high level, the microcomputer 54 Based on the judgment that each circuit system A, B, and C is normal, the computer program is executed at step 113.
Then, the third output signal is extinguished and the first output signal is generated. Therefore, the pseudo signal generation circuit 60 eliminates the pseudo signal by making the transistor 61 non-conductive, and the transistor 71 also causes the microcomputer 5
4 conducts and shorts high resistor 72. As a result, the startup device S is placed in a startup ready state.

As explained above, in addition to the failure detection circuit 50, both the pseudo signal generation circuits 60 and 80 are employed, and when the device of the present invention is normal, pseudo signal generation occurs when the pseudo signal from the pseudo signal generation circuit 60 disappears. The level of the acceleration amplified signal generated from the amplifier 20a based on the generation of the pseudo signal from the circuit 80 is made lower than the reference voltage from the pair of series resistors 31a and 31b, and the pseudo signal from the pseudo signal generation circuit 80 is eliminated. The level of the pseudo signal from the pseudo signal generation circuit 60 below is higher than the reference voltage from the pair of series resistors 31a and 31b, and the comparator 51 outputs a comparison output with respect to its re-input level.
Since the internal failure of the device of the present invention is checked in relation to the comparison output for the re-input level by the comparator 53 and the comparison output for the re-input level by the comparator 53, the transducer is used for the primary check of the device of the present invention. Without the output from the user 20, it is possible to separately recognize the presence or absence of a failure in each of the circuit systems A, B, and C.

Furthermore, in the short circuit state of the high resistance 72 after step 113 described above, the comparison signal from the comparator 53 is maintained at a low level, so the microcomputer 54 repeats the determination "rYES" in step 114. When the comparison signal of the comparator 53 is inverted to high level from this state, the determination in step 114 becomes "NO".
”, and the microcomputer 54 advances the computer program to step 115. Here, high resistance 7
The fact that the voltage at one terminal 11 of the starting element 10 inverts the comparison signal of the comparator 53 to a high level under the short circuit of the starting element 10 indicates that the starting element 10 is activated. This step 1
At step 15, if both the comparison signal from the comparator 51 and the comparison signal from the comparator 52 are at high level, it is determined that activation of the activation element 10 is due to a normal acceleration signal from the transducer 20. Therefore, if the comparison signal from the comparator 51 is at a low level and the comparison signal from the comparator 52 is at a high level, the microcomputer 54 selects r
It is determined as YESJ, and in step 116, it is determined that the transistor 61 has a conduction failure and is stored. On the other hand, step 11
If the determination in step 5 is rNOJ (that is, the comparison signals from both comparators 51 and 52 are both at low level), the microcomputer 54 determines rNOJ in step 115, and in step 117 the transistor 41 is determined to be a continuity failure and stored.

In this way, when the determination in step 114 becomes rNOJ while repeating the determination of rYESJ in step 7 step 114, both comparators 51 and 52
Since the level of the comparison output for each input level is determined by , the activation of the starting element 10 due to a conduction failure of the I-transducer 41 or 61 is replaced by the activation of the starting element 10 due to the acceleration signal from the I-transducer 20. can be reliably identified.

Also, as described above, in step 114 [YESJ
If an abnormal change occurs in the running speed of the vehicle in a state where the determination is repeated, [・Transducer 2
The acceleration detection signal generated from 0 is amplified by the amplifier 20a as an acceleration amplification signal, passes through the buffer 20b, and is input to the operation determination circuit 30 as an acceleration buffer signal. When a low level comparison signal is generated from the comparator 33 of the operation determination circuit 30, the operation switch circuit 4
0 short-circuits the high resistance 42 due to conduction of the transistor 41. Therefore, the starting element 10 ruptures the gas generator G due to an increase in the inflow current, and supplies gas from the gas storage source into the gas bag Bg, thereby inflating the gas bag Bg as shown in FIG.

As described above, according to this embodiment, the level of the pseudo signal generated by the pseudo signal generation circuit 80 is actually
1 is set not to conduct, and this pseudo signal is detected by the comparator 51. Therefore, if the comparator 53 detects that the starting element 10 has actually been activated for some reason, the activation is detected by the transformer. Is it due to the acceleration signal from the deuser 20?
Alternatively, it is possible to identify whether this is due to a circuit abnormality after the amplifier circuit 20a based on the comparison signal from the comparator 51.

In addition, in carrying out the present invention, the present invention may be applied to a starting device for a seatbelt 1- of a vehicle.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to the configuration of the invention described in the claims, FIGS. 2 and 3 are overall configuration diagrams showing an embodiment in which the present invention is applied to a vehicle gas bag system, and FIG. 4 is a flowchart showing the operation of the microcomputer shown in FIG. 3; Explanation of symbols: Ba...Battery, Bg...Gas battery, G...
- Gas generator, 10... Starting element, 20... Acceleration sensor, 20a... Differential amplifier, 30... Operation determination circuit, 40... Operation isochi circuit, 51.52...
・Comparator, 54...Microcomputer, 5
1a, 51b, 52a, 52b--Series resistance, 60.
80---Pseudo signal generation circuit. Applicant Nippondenso Co., Ltd. (1 other person) Agent Patent attorney Teru Hase - Figure 1

Claims (1)

[Claims] It has a starting element that is installed in the cabin of the vehicle and is activated selectively in response to an inflow current from a DC power source, and an operating mechanism that operates to protect the occupants in response to activation of the starting element, and an acceleration detection means for detecting acceleration and generating it as an acceleration detection signal; a determination means for determining when the level of the acceleration detection signal exceeds a reference level and generating a determination signal; a current supply means for supplying current from a power source to the starting element; a signal provision permitting means for permitting only a signal to be given from the acceleration detection means to the determination means; between a first pseudo signal generating means for generating a first pseudo signal so as to pseudo generate an acceleration detection signal at a first different level different from a reference level, the signal provision permitting means and the determining means; a second pseudo signal generating means for generating a second pseudo signal at a second different level having a level opposite to the first different level with the reference level as a reference; and when the second pseudo signal disappears; When the first pseudo signal is generated, the presence or absence of a failure in the input circuit system is determined based on each output level of the acceleration detecting means and the signal provision permitting means in relation to the reference level, and the first pseudo signal disappears. and determining means for determining whether or not there is a failure in the remaining circuit system based on the input/output level of the signal provision permitting means in relation to the reference level when the second pseudo signal is generated at the bottom. A failure determination device for a vehicle occupant protection system characterized by: